1. Field of the Invention
The present invention relates to an apparatus for separation of ferromagnetic materials from fluid media.
2. Description of the Related Art
There is known an apparatus for separation of ferromagnetic materials from fluid media, (SU, A, 1029990). It comprises a cylindrical working chamber externally accommodating a magnetizing system and internally incorporating a ferromagnetic attachment made in the form of plates with openings. The working chamber is provided with connections for intake of the fluid medium to be purified and for discharge of the purified fluid medium.
In the known apparatus the plates with openings are equally spaced throughout the height of the working chamber, and gaps are formed between the plates for passing the flow of the fluid medium being purified. The impurities are precipitated out of the medium being purified at the edge of the openings in the plates where zones of nonuniform magnetic field are set up. However, the effect of the nonuniform magnetic field forces on the foreign particles in these zones is not substantial. Besides, all the zones of the nonuniform magnetic field have approximately one and the same nonuniformity throughout the volume of the working chamber which prevent the fluid media containing impurities with a different degree of dispersity and different magnetic properties from being effectively purified, as the removal of such impurities requires different nonuniformity of the magnetic field throughout the volume of the working chamber.
Further in the known apparatus the plates are rigidly secured to one another and have no possibility of mutual displacement and separation from one another which prevents an effective regeneration and consequently a qualitative washing of trapped impurities away from the plates.
Also known to the prior art is an apparatus for separation of ferromagnetic materials from fluid media, (SU, A, 1152618), comprising a working chamber internally accommodating a ferromagnetic attachment in the form of a multitude of plates with through openings provided along the circumference with shaped projections oriented at an angle to the plane of the plates, a magnetizing system adapted for interaction with the ferromagnetic attachment and for its magnetizing, an inlet connection for delivery of a fluid medium to be purified in the working chamber and an outlet connection for receiving the purified fluid medium after it passed through the attachment.
In the known apparatus the plates with openings of equal sizes comprise shaped projections forming a multitude of zones of the nonuniform magnetic field, the value of which, in these zones, is greater by an order of magnitude than in the plates with the openings having no projections. This apparatus is effective in purification of fluid media containing foreign particles similar in size and magnetic properties. If the medium to be purified is changed and contains foreign particles of other sizes and properties, it calls for changing the plate attachment with another one having plates with openings of other sizes and spacing, and other shaped projections. Viscosity of a medium to be purified also exerts a substantial influence on the effectiveness of purification and on selection of the attachment. The use of plates with openings and projections of similar sizes and spacing results in that, in the apparatus engaged in purification of fluid media, portions of the attachment volume throughout the height of the working chamber take an unequal share in the purification mode. The lower portions (adjacent to the inlet connection) are clogged with impurities rapidly, the middle portions, slowly and the upper portions (adjacent to the outlet connection) are clogged still more slowly. In this case the time between the two subsequent regeneration periods will be determined by operation of the lower plate layers of the attachment, i.e. the filtration cycle will be reduced.
Also the majority of the real fluid media to be purified contain foreign particles with the sizes thereof varying in a wide range from 0.01 to 10 .mu.m and upward, while the required degree of purification of the fluid media, for example, a circulating water in the metallurgy or condensates of thermal power stations should be brought up to a residual content of impurities within 10.sup.-4 -10.sup.-9 fraction of the total mass. Besides the impurities possess different magnetic properties: from paramagnetic to ferromagnetic, and the fluid media to be purified are varying from gases to condensates and oils which have different viscosity. Due to the design features the known apparatus cannot provide the required degree of purification of the media containing impurities of different sizes and different magnetic properties, and fails to ensure equally effective conditions of purification throughout the entire volume of the attachment.